Grommet



' Maak 2, 1943.

D. F. SHEPHERD l GROMMET Fil'ed Aug. 26, 194V www@ Patented Mar. 2, 1943 f GRQMMET Daniel F. shepherd, united states Army,

Richmond, Va.

Application August 26, 1941, Serial No. 108,336

(Granted under the act of March 3, 1883, as

amended April 30, 1928; 370 0. G. 757) 1 Glalm.

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to a grommet and means for securing the same to protect the rotating hands of shells.

Modern artillery projectiles are conventionally provided with rotating bands the purpose of which is to seal the bore around the projectile` against the escape of gas and to engage the rifiing of the bore to transmit rotation to the shelL It will be readily apparent that, if the rotating band or bands are accidentally deformed prior to ring, such deformation will have a 'serious eiect upon the accuracy of the ight of the projectile and tend to greatly increase erosion of the gun bore.

Accordingly it is the object of this invention to produce an improved means for protecting projectile rotating bands, which means can be economically manufactured and conveniently applied and removed.

A further object is to produce a protective member which can be readily applied to the protection of shaft bearing surfaces, 'pipe threads and the like.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawing in which:

Figure 1 is an elevation, partly in section of the preferred embodiment of my invention;

Figure 2 is an end elevation of the device shown in Figure 1.

Figure 3 is a view. similar to Figure 1 showing a modified form of securing means.

Figure 4 is a fragmentary end elevation of the device of Figure 3.

Figure 5 is a fragmentary cross section showing the details of the cushioning member illustrated in Figs. 1 and 3.

Figures 6 and 7 are fragmentary cross sections showing modifications of the cushioning member as applied to other forms of rotating bands.

Referring to the drawing by characters of reference the grommet comprises a flexible split band I of steel or other material having a cushioning member II secured therein and provided with resilient securing means comprising the spring members I2 and I3. In the preferred embodiment. as shown in Figs. 1 and 2 the spring member l2 is provided at one end with a hook It engaging the loop I formed in the surface of the band I0 and at the other end with an eye I6 to engage the member I3. The member I3 is preferably formed by twisting a single piece of spring wire upon itself to form a handle portion ,having a hook I8 at the doubled end of -the wire and diverging leg wires forming a senil-circular section I9 terminating in end sections 20 to be inserted in loops 2l formed in the surface of the band I0. A similar loop 22 is provided to engage the hook member I8.

In the employment of the grommet described above the band I0 is opened sufficiently to permit it to be slipped over the projectile body 8 to a position in which the cushioning member II engages the rotating bands 9. The handle portion of the member I3 is engaged in the eye I6 of the member I2 and the member I3 drawn into a position in which the hook I8 is engaged in the loop 22. As the member I3 is preferably formed of highly resilient material such as spring steel, the give in the semi-circular section I9 will provide tension to keep the grommet securely engaged with the rotating bands. Further, such a construction will be inherently self-adjustable to accommodate itself to minor variations in the length of the split band. The grommet .may be readily released by springing the handle laterally far enough to allow disengagement of the hook I8 from the loop 22.

In the modied form of my invention shown in Figs. 3 and 4 the securing means comprises a member 32 substantially similar to that shown as I2 in Figure 1 and a member 33 which is a modified form of that shown as I3 in Fig. 1. In this form of the invention a straight section of spring wire 23 is engaged in a loop 24 at one extremity of the band I0. The ends of the wire are brought together to form a semi-circular portion 25 and a handle portion of double wire. A hook 26 may be provided in the band I 0 under which the end of the arm may be engaged. This modication of the invention may be employed in the same manner as that described above in connection with Figures 1 and 2.

In Figure 5 a detail cross section illustrates the I form of the cushioning 'member indicated generally as II on Figures 1 to 4. This cushioning l member is shown as applied to a projectile body.

8 having a pair of rotating bands 9. A wide strip of cotton` webbing 21 may have secured to it by sewing or other methods a plurality of narrower strips 28 to engage the projectile body between A.

ioning bands built up by securing together a plurality of laminar strips to obtain the contours necessary for engaging projectiles having rotating bands of diil'erent sectional form.

Obviously the cushioning member may be molded as a unit from rubber or any suitable plastic material to the exact form needed lto t the rotating bands after which it may be secured to the split band in any desired manner.

I claim:

A grommet for protecting the outer surface of cylindrical metal objects comprising a split ring having cushioning means secured tothe inner CII , Figures 6 and 7 show modied forms of cushl perimeter thereof, a lever of exlble material formed with a central operating arm and laterally diverglng arms having pivotal connection with one end of the ring substantially coextensive with the width ofthe ring, a link loosely connected with the lever at the juncture of the diverging arms and the operating arm, the oppositevend of the link being loosely connected with the central portion of the other end of the ring, and means carried by the lever end of the ring into and out of engagement with which the lever arm is flexed to lock or unlock the lever.

DANIEL F. SHEPHERD. 

